Machine for making elastic yarn



MACHNE FOR MAKING ELASTIC YARN Filed Feb. 3, 1939 i a jf o g/f/ ZZ/Z7 jif M Mimo m Patented Aug. 13, 1940 UNITED STATES PATENT OFFICEManchester, Providence,

R. I., assignors to United States Rubber Company, New York, N. Y., acorporation of New Jersey Application February 3, 1939, Serial No'.254,400

1 Claim.

The present invention relates to a machine for making a balanced singlecover elastic yarn in one continuous operation.

It has been proposed heretofore to make a bal- 5 anced elastic yarnconsisting of a rubber core ltwisted in one direction and having atextile cover forming helical windings extending in the oppositedirection to balance the twist of the core. In these priorconstructions, however, the rubber core has been twisted in oneoperation and then the covering hasbeen applied thereto in a separateand distinct operation, or the elastic yarn has been produced byhelically winding a covering yarn about an untwisted core and then thiselastic yarn has been subsequently balanced by twisting the core andcover in the opposite direction.

In an elastic yarn such as herein contemplated, in which the twistsimparted to the rubber core in one direction are relied upon to balancethe helical windingsA of theA cover in the opposite direction, it isnecessary to accurately control the number of twists per inch impartedto the rubber core and also to control the tension or amount of stretchimparted to the rubber core at the time the cover is being woundthereupon.

The present invention contemplates a simple and practical machine forproducing a single cover elastic yarn in one operation by removing therubber thread endwise from a rapidly rotating package so as to twist thecore and control the amount of twist imparted thereto,.and at the sametime stretch this twisted rubber thread to a desired degree andhelically winding the textile cover upon the stretched portion of therubber core, to thereby produce a balanced elastic yarn in which theconditions attending the twisting of the core and applying the coverthereby are accurately controlled,

A primary feature of the present invention resides in mechanism forrapidly rotating the package of rubber thread and in feedl means fordrawing the thread endwise from the package at a uniform speed tothereby accurately control the twist per inch imparted to this thread,and also in second feed means spaced from the first and operable toaccurately control the tension of the portion of the twisted threadabout which the cover isrbeing helically wound.

As a result of the present construction the various steps of producingthe elastic yarn are performed in one continuous operation andanexcellent control of the rubber core is secured throughout its travelfrom the let-od package to the winding vof the finished elastic yarnupon its take-up package.

The various features of the present invention and novel combination ofparts will be more fully understood from the following description whenread in connection with the accompanying drawing illustrating one goodpractical form thereof.

In the drawing:

Fig. 1 is a diagrammatic side elevation of one form of the machine forcarrying out the invention; and

Fig. 2 is an enlarged side elevation of a piece of elastic yarn formedupon the machine of Fig. 1.

In the embodiment of the invention illustrated in the drawing, theelastic thread I0 formed of rubber or any other suitable rubberlikematerial is wound in an untwisted condition upon a spool I I to therebyform a package which Vpreferably is small enough to permit the same tobe rotated at high speed, say 10,000 R. P. M. or higher. The rubberthread should be wound upon this spool under sufficient tension toprevent the entire mass of rubber from ballooning or bulging outwardlyappreciably from the body of the spool under the centrifugal forcecaused by the high speed of rotation.

In the construction shown, the thread supply spool II is mounted uponand is rotatably supported by the spindle I2 which maybe rotated by adriving belt, but isV preferably driven at high speed by a smallelectricmotor I3.

It is found unnecessary to provide a ring and, traveller or a guidingier to control the thread III as it is unwound from the spool II, sincethe unwinding of this thread and ballooning of the same can becontrolled by providing a pigtail or guide I4 mounted in axial alignmentwith the spool II and a short distante therefrom.

As above stated, an important feature of the present invention residesin feed means for accurately controlling the speed at which the rubberthread I0 is withdrawn endwise from kits package to thereby control thenumber of twists per inch imparted to this thread. In the embodiment ofthe invention shown, this thread feeding means consists of thecooperating rolls I5 and I6 between which ythe rubber thread III passes.The lower feed roll I5 may be driven by any suitable means and is shownas driven by its engagement with the driving roll I1. The rolls I5 andI6 are rotatably supported by the bracket I8 so that the roll I6 mayrest by gravity upon the thread passing between it and the parted to therubber thread I can be accuratelyA controlled. It should also be notedthat theballooning of the thread I0 will help to take up slightvariations in the tension of this thread as it unwinds from the packageIl.

The mechanism so far described serves to impart the desired amount oftwists to the rubber thread ready to have the cover wound thereupon inthe opposite direction but, as above stated, it is important toaccurately control the tension of the portion of the twisted thread Aabout which the cover is being applied. This is secured, in theconstruction shown, by employing the second feed means which may -besimilar in construction and operation to the first feed means justdescribed. This second feed means, as shown, consists of the drivingroll I9 above which is provided a pair of feed rolls 20 and 2l. Thesefeed rolls are supported by the bracket 22 to be driven by the roll I9as the elastic yarn passes between the rolls I9 and 26 and then upwardaround the roll 20 and between it and the upper roll 2|. The arrangementis such that the rolls 20 and 2I rest by gravity upon the elastic yarnthey are feeding. It will be seen that by operating the driving roll I9at the proper speed with respect to the lower driving roll I'I theamount of stretch imparted to the twisted rubber thread I0 at this timemay be accurately controlled. Various forms of covering mechanism may beemployed to wind a cover such as textile yarn 23 about this stretchedportion of the twisted rubber core. This covering mechanism in theconstruction shown, comprises an electric motor 24 adapted to rotaterapidly the hollow spindle 25 upon which is mounted the package 26 ofcovering yarn. In this construction a ring 21 and traveller 28 areprovided for 'guiding the covering yarn 23 as it unwinds from thepackage 26 and they serve also to wind this yarn about the tensionedrubber core I0.

The arrangement is such that the rubber thread I0 passes upwardlythrough the hollow spindle 25 to the yarn guide 29 and the rotation ofthe yarn package 26 serves to wind the cover 23 about the twisted rubbercore in the opposite direction to the twist of the core so as to causethe helical windings of this cover to balance the twists of the core andthereby produce a balanced elastic yarn. The let-off package II may berois driven in the construction shown by resting upon the driving roll33 and the drum 32 is rotatably supported by its central shaft 34 whichrests in the slotted portion of the supporting bracket 35.

The machine of the present invention has been designed more particularlyfor the manufacture 'of a iine elastic yarn and the operating motors I3and 24 are preferably constructed to operate at high speed. It istherefore important to provide each motor with brake means [for quicklystopping its rotation after the power has been cut off. Therefore, inthe construction shown, the motor I3 is provided at the lower end of itsoperating spindle I2 with a friction disc that rotates with this spindleand which is adapted to be frictionally engaged by the braking member 36secured to the outer end of a flexible brake applying rod 31. Likewisethe motor 24 is provided at the lower end of its operating spindle 25with a brake disc adapted to be frictionally engaged by the brake member38 carried at the outer end of the flexible brake applying rod 39.

In the construction shown, the feed roll supporting brackets I8 and 22,the drum supporting bracket 35 and the brake applying rods 31 and 39 areall secured to a Vertical operating rod 40. The arrangement is such thatwhen it is desired to stop the winding operation, the rod 46 is movedupwardly slightly to thereby apply the brakes 36 and 38, move the feedrolls out of engagement with their driving rolls and lift the skeinreceiving drum 32 out of engagement with its driving roll 33.

It will be seen from the foregoing that the mechanism of the presentinvention is simple in construction and well adapted to give accuratecontrol of the amount of twist imparted to the rubber thread I0 as it isunwound from its supply spool II, and that it is also well adapted tomaintain the twisted portion of the rubber core under the desiredtension or degree of elongation while the cover is being helically woundthereupon. This serves to produce the single cover balanced elastic yarnshown in Fig. 2 in which the twists of the rubber core I0 in onedirection serve to balance the` helical windings of the coveringmaterial or covering yarn 23 in the opposite direction. v

In order that the type of elastic yarn that may be produced on thepresent machine may be better understood the following examples aregiven.

tated in either a clockwise or contra-clockwise direction so long as thepackage 26 is rotated in an opposite direction to applythe cover in adirection to balance the twist of the core.

The finished elastic yarn, thus produced, passes between the feed rolls2l and 22 as above described, and then through the yarn guide 3l!4 whichis mounted upon the traverse bar 3| to traverse this elastic yarn as itis wound into a skein about the take-up drum 32. This drum Core-rubberthread 1150's.

over 1 end 100 1 cotton. 3 Yds./lb.`elastic yarn.. 20,000. l 4Elongatlon... 125%. 5 Length oi core 1n one yard of elastic yarn... 20ins. 6 Percent core .i 3 7 Percent cover 50. 8 Gaugeelastic yarnrelaxed.. 0.008". 9 Elastic yarn strength at break Having thus describedour invention, what we claim and desire to protect by Letters Patent is:

In an apparatus for making a balanced elastic yarn having a singlecover, in combination, a let-01T package for a rubber thread, powerdriven means for rotating said package about its central longitudinalaxis to twist the thread, powerdriven thread gripping rolls for drawingthe thread endwise of said package at a uniform speed to impart a.denite number of twists per inch to the thread, other power-driventhread gripping rolls spaced from said rst rolls and operable to stretchthe portion of thread extending therebetween a predetermined amount, anda hollow spindle through which said thread passes and operable to Wind acovering strand helically

